Acceleration pump



A 43- H. A. BOLLER ACCELERATION PUMP Filed July 25, 1940 I III/III AVI INVENTOR v HENRY ABOLLER ATTQRNEY Patented Aug. 17, 1943 UNITED ACCELERATION PUMP Henry A. Boiler, Walled Lake, Mich, assignor to Carter Garburetor Corporation, St. "LouiSJVIo. V a corporation of Delaware H Application July 2a, 1940. Serial No.1846386 2 Claims.

This invention relates to fluid pumps and .consists particularly in novel acceleration pump structure for carburetors. i

Accelerating pump pistons actuated by resilient means often become stuck and cease to function. There is considerable time and labor expended in breaking the piston loose and removing any ob-' jectionable gum that has been allowed to accumulate by the inactivity of the pump piston.

An object of this invention is to provide a novel accelerating pump of the spring actuated type having additional spring means for providing a strong initial actuation. I

Another object is to provide a spring actuated accelerating pump including means for positively actuating the pump in case it becomes stuck.

These objects and other more detailed objects hereafter appearing are attained by the structure illustrated in the accompanying drawing in which: 7

Fig. 1 is a vertical sectional View of an internal combustion engine carburetor taken substantially on line in Fig. 2 with portions bro-ken away.

Fig. 2 is a plan view of the carburetor.

Fig. 3 is a side elevation of the carburetor with portions broken away.

The carburetor illustrated comprises a downdraft mixture conduit including an air inlet horn venturi 2, an outlet portion flanged at 3 for attachment to the intake manifold (not shown) of an associated engine. A choke valve 4 is pivotally mounted in the air horn and throttle valve 5 is pivoted near the outlet portion on shaft 6.

Any suitable means may be employed for oper ating the choke and throttle valves other than the cranks and 8, respectively. Adjacent the mixture conduit is a bowl 9 within which fuel is maintained at a substantially constant level by the usual needle valve l actuated by the float Located within the float bowl is an accelerating pump l consisting of pump cylinder l6, and a pis- Fuel enters the pump chamber l9 .from'the fuel bowl. through a screenedrinlet passage 23. controlled by'checkld and, is discharged past the outlet check through a nozzle 26 into the mixture conduit adjacent the venturis. The inlet and outlet checks communicate with pump chamber l9 through passages 21 and 23.

Pump piston I5 is connected to the throttle valve through the intermediary of piston rod 30 and lever 3|, pivoted to pillow block 32 projecting above the float bowl cover and connected to crank 33 rigid with the throttle shaft by means of a link Piston rod 30 slidably received through the bowl cover 22 has one end rigidly secured to pump piston I5 while the other end is connected to the lever 3| by a link 35.

Lever 3| pivoted on the shaft 36 of pillow block 32 is adapted and arranged to actuate the usual metering rod 31 extending through the bowl cover 22. Also lever 3| is provided with a slot 38 for slidably receiving one end of link 35.

By opening the throttle very slowly the rate of downward travel of piston |5 will be controlled by the throttle. By opening the throttle rapidly the rate of'downward travel of piston l5 will be controlled by the compression springs 20 and 2| as link will slide in slot 38 and lever 3| will exert no downward pressure upon piston I5. If, however, piston l5 becomes stuck and the throttle valve is opened, link 35 will slide the full length of slot 38 whereupon the lever 3| will exert a positive pressure upon piston IE to dislodge it.

It is to be noted that prestressed springs 2|) and 2| exert a great initial pressure on piston l5 which gradually diminishes as the piston proton I! of the air dome type and having a spring pressed packing and an air dome |8 for receiving a portion of the fuel as the fuel in the compression chamber I9 is subjected to pressure by a downward thrust of the piston. Springs 20 and 2| are compressed or pretensioned between the piston l5 and the fuel bowl cover 22 and constantly urge the piston l5 downwardly to discharge the pump. It is to be noted that spring 2| is shorter and grosses downwardly and the limit of travel is governed by the degree of throttle opening. The throttle may be opened a predetermined distance more rapidly than the springs 20 and 2| are capable of thrusting the piston |5 downwardly a corresponding distance therefore the time consumed for discharge of fuel from the pump will be much greater than if the throttle were positively connected to the pump. Air confined in stronger than spring 20 and is 'fully extended. before piston reaches the end of its downward:

stroke. By the use of spring 2| greatertinitial pressure is exerted upon the piston during'lthe' first part of the opening movementof the throttle air dome l8 compressed by the downward movement of piston |5 also contributes to the continued discharge of the pump after the downward travel of piston l5 has been stopped by the Modifications in many respects will occur to those skilled in the art and the exclusive use of all such modifications as come within the scope of the appended claims is contemplated.

I claim: 7

1. In a carburetor, an induction conduit having a throttle therein, a throttle actuator, an accelerating pump having a piston, connecting means between the throttle and said piston for moving said piston to discharge position as said throttle is closed, said connecting mean including a lever having a fixed pivot actuated by movement of said throttlesaid lever having a guideway constructed and arranged to assume an inclined position when said throttle is substantially closed, a link member carried by said piston and engaging said guideway to form a lost motion connection between said lever and piston, said lever being shiftable on its pivot upon opening movement of said throttle to move said guideway towards a vertical position, and a spring normally moving said piston in its discharge direction as said guideway is shifted to permit movement of the pump connection. 2. In a carburetor, an'induction conduit having a throttle therein, a throttle actuator, an accelerating pump having a piston, connecting means between the throttle and said piston for moving said piston to discharge position as said throttle is closed, said connecting means including a lever having a fixed pivot actuated by movement of said throttle, said lever having a guideway constructed and arranged to assume an inclined position when said throttle issubstantially closed, a link member carried by said piston and engaging said guideway to form a lost motion connection between said lever and piston, said lever being shiftable on its pivot upon opening movement of said throttle to move said guideway towards a vertical position, a spring normally moving said piston in its discharge direction as said guideway is shifted to permit movement of the pump connection, and an additional spring loosely arranged between the piston and the upper end of the cylinder initially urging said piston in its discharge direction and proportioned to be fully extended before the piston reaches the end of its downward movement.

' HENRY A; BOLLER. 

